Research on compound semiconductors, beginning with Gallium Arsenide, started at Cornell in 1965. Emphasis has been on pure device-quality material, abrupt heterojunctions, and novel structures for microwave transistors and lasers. There have been 111 PhD and 41 MS degrees granted, and the effort of several senior staff members, and 81 visiting scientists were involved. Most are in U.S. industry and universities, with some in Europe and in the Far East. A substantial fraction of these participants have been involved in the industrial developments leading to the $15-20 Billion annual business in the compound semiconductor areas. This paper covers selected technical results from this early and extended Cornell program in this field.